Soy is one of the most widespread food additives, which makes it tough to avoid if you have a soy allergy. It’s also unsettling to think that eating something that contains soy can lead to a life-threatening allergic reaction. Fortunately, many people grow out of their soy allergies as an adult. In the meantime, arm yourself with the basic facts about the symptoms of soy allergy, when to call your doctor, and how to avoid eating the multitude of foods that contain soy.
How Will I Know If I Have a Soy Allergy?
You will need to see your doctor to diagnose soy allergy, but certain symptoms may suggest that you have the condition. Call your doctor if you have any of these symptoms soon after eating or drinking foods that contain soy:
Feeling queasy or throwing up
Loose or runny stools
Pain in your stomach or abdomen
Runny or stuffy nose
Anaphylaxis is a very serious type of allergic reaction that affects your whole body. Call 911 for immediate emergency care if you have any of these symptoms:
Feeling dizzy or passing out
High-pitched whistling as you breathe
Large areas of raised welts on the body or face (hives)
Swollen or tingling throat, tongue or lips
Trouble talking or raspy voice
To diagnose a soy allergy, your doctor will ask you questions about your medical history, eating habits, and your symptoms. He or she will also need to perform a physical exam and some tests to diagnose your symptoms.
One indicator of a soy allergy is a skin test. Your doctor will put different substances on your skin to see what causes a local reaction. Skin testing alone does not determine if you have a soy allergy. Your doctor will consider all the information gathered in your office visit to make a diagnosis.
Who Gets a Soy Allergy?
Soy is one of the eight foods—along with milk, eggs, peanuts, tree nuts, wheat, fish, and shellfish— that account for 90% of all food allergies in the United States (Source: AAAAI). In some people, the body produces IgE-type antibodies to proteins found in soy. Each time you eat soy products, your immune system reacts with the specific IgE antibodies and tries to eliminate the soy from your body. This reaction causes the unusual symptoms associated with soy allergy.
Many soy allergies begin in infanthood as a reaction to baby formula made with soy. You or your child might have a greater risk of soy allergy if there is a personal or family history of food allergies, such as wheat, beans, and milk. A personal or family history of allergy-related conditions, such as eczema or asthma is also a risk factor.
What Foods Should I Avoid If I Have a Soy Allergy?
Soy is a very common ingredient in foods. In addition, in can be a staple item for a vegan diet. If you or someone you cook for is allergic to soy, you will need to read food labels and watch for the word “soy.” You’ll also want to ask about soy ingredients when eating out:
In addition, be aware that many Japanese dishes also contain soy including:
Edamame (soybeans in the shell)
Textured vegetable protein (TVP)
Vegetable gum, broth or starch
If you are unsure about any food, don’t eat it until you ask your doctor.
What Are Some Good Soy Substitutes?
Unfortunately, having a soy allergy makes it more likely that you are also allergic to other types of foods. For example, wheat, peanut, milk and dairy products are not always good substitutes for soy products. If you’re trying to find a good protein (and vegan) substitute for soybeans try black, pinto or kidney beans.
If you undergo allergy testing you can find out if you are allergic to other foods as well. You can also ask your doctor about what products are safe for you.
When Should I Call My Doctor?
If you suspect that you, or your child, have symptoms of a soy allergy, call your doctor right away. An early diagnosis and treatment can help prevent serious reactions.
If you are diagnosed with a serious soy allergy you should carry injectable epinephrine at all times. If you have serious symptoms, such as dizziness or shortness of breath, inject yourself with your epinephrine medication as directed. Even if your symptoms get better, call 911 for emergency follow-up care to ensure your symptoms do not return.